The present invention concerns a system for automatically manufacturing reclosable flexible bags of the type having reclosable interlocking zipper profiles. More particularly, the invention concerns a system that continuously and automatically produces individual bags and packages the bags in a shipping container or box.
In the manufacture of reclosable flexible bags, the bags are usually formed from an extruded sheet of plastic film. Flexible interlocking zipper profiles can be formed inside the top edges of the bag, such as described in U.S. Pat. No. Re. 28,959 to Naito. Alternatively, the zipper profiles can be separately extruded and then sealed adjacent the top edges of the bag. In some applications, the fastener profiles are continuously sealed on the inside surface of the bag. In other applications, such as that described in the patent to Branson, U.S. Pat. No. 4,787,755, the fastener profiles are sealed at their ends to the side edges of the bag.
One typical bag manufacturing process and apparatus is shown and described in U.S. Pat. No. 4,787,755. In this process, a roll of plastic film is provided to the manufacturing apparatus and is advanced through the several stages by commonly known powered rollers. While the process and apparatus of the Branson patent shows the simultaneous production of pairs of bags, a similar process can be employed in the manufacture of single bags having fastener profiles adjacent their top openings.
It is common in most bag manufacturing processes that the finished bags are directed to a loading table where the bags are manually loaded into shipping containers or boxes. This manual loading technique results in high labor costs since human intervention is required. In addition, the manual loading technique can reduce the speed of bag production since the speed of the manual loading is typically one of the limiting features of bag processing and packaging speed.
One aspect of packaging the newly produced reclosable bags that decreases the manual loading time is that the bags should optimally be packed in alternating opposing relation. The zipper profiles increase the thickness of the bag adjacent the top of the bag so that if the bags are stacked in the same orientation, fewer bags can be packed into a given shipping container. Thus, in order to increase the bag count within a shipping container, it is preferable that the bags be alternatingly arranged so that the zipper profiles between consecutive groups of bags are at different orientations.
There is a need in the industry for an automatic bag manufacturing and packaging machine that can eliminate the need for human intervention as much as possible from start to finish in the production and packaging process. There is also a need for a machine that can optimally package reclosable bags into a shipping box so that the greatest number of bags can be stacked within the container.